This invention relates to a method of defining metallized patterns on a substrate in general and particularly to a method that does not use masks or resist to delineate metallized areas. When applying metallization to a substrate such as by vacuum metallization operations, the delineation of metallized areas is accomplished either by the use of masking tools or by photoresist application which requires exposure and developing. For example, a molded resonator having metallized outer areas, is illustrated in U.S. Pat. No. 4,751,481, the disclosure of which is incorporated by reference. In this patent isolated electrical areas are provided by applying resist to depressions which define islands that are to be electrically isolated from the metallization of the ground plane on the resonator. Sputtering or vacuum deposition is then utilized to apply the metallization to the member. The resist prevents the metallization from adhering at the locations where the resist has been applied. Consequently, electrically isolated metallized areas are provided as defined by the applied resist. Such a technique requires the application of resist to the member prior to metallization. It would be advantageous if this step could be eliminated while still providing electrically isolated areas after metallization.